visible light-photosensitized oxidation of organic pollutants ......1 supplementary data for visible...

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Supplementary Data for

Visible Light-Photosensitized Oxidation of Organic Pollutants

Using Amorphous Peroxo-Titania

Jiwon Seo a, Hongshin Lee a, Hye‒Jin Lee a, Min Sik Kim a, Seok Won Hong b, Jaesang Lee c,

Kangwoo Cho d, Wonyong Choi d, Changha Lee a,*

a School of Urban and Environmental Engineering, KIST-UNIST Ulsan Center for

Convergent Materials (KUUC), Ulsan National Institute of Science and Technology

(UNIST), Ulsan 44919, Republic of Korea

b Center for Water Resource Cycle Research, KIST School, University of Science and

Technology (UST), Korea Institute of Science and Technology (KIST), Seoul 02792,

Republic of Korea

c Department of Civil, Environmental, and Architectural Engineering, Korea University,

Seoul 02841, Republic of Korea

d School of Environmental Science and Engineering, Pohang University of Science and

Technology (POSTECH), Pohang 37673, Republic of Korea

*Corresponding author

Tel.: +82‒52‒217‒2812

Fax: +82‒52‒217‒2809

E‒mail: clee@unist.ac.kr

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Text S1. Analytical Method of LC/MS

Chromatographic separation was performed on a 2.1 × 150 mm, 5 μm C18 column

(AcclaimTM 120 C18, Thermo Fisher Scientific Inc.), using 0.1% (v/v) formic acid solution

and acetonitrile as the eluent with a 65:35 ratio at a flow rate of 0.3 mL/min. The heated

electrospray ionization source interface was operated in the negative ionization mode under

the following conditions: spray voltage = 3.1 kV, sheath gas = 40 arbitrary units, auxiliary gas

= 10 arbitrary units, sweep gas = 0 arbitrary units, capillary temperature = 320˚C, S-lens RF

level = 65.0 arbitrary units and vaporizer temperature = 300˚C. Mass spectra were obtained in

full scanning mode from 50 to 230 m/z at a resolution of 35000, an automatic gain control

target value of 5×104, and a maximum injection time of 100 ms. All data acquisition and its

processing were performed using Xcalibur 3.0.2 software (Thermo Fisher Scientific Inc.).

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Table S1. Products of 4-CP degradation by visible light-illuminated Am-peroxo-TiO2 identified by HPLC and LC/MS analyses.

ProductNo.

Compounds Chemical formula

Theoretical m/z

Observed m/z

Δ (ppm) Ionization

form Analysis method

1 Benzoquinone C6H4O2 107.0138 108.0206 -11135.01 [M]- HPLC, LC-MS

2 Hydroquinone C6H6O2 - - - - HPLC

3 Hydroxybenzoquinone C6H4O3 123.0087 123.0075 9.76 [M-H]- LC-MS

4 Hydroxyquinol C6H6O3 125.0244 125.0236 6.40 [M-H]- LC-MS

5 2,5-Dihydroxy-1,4- benzoquinone C6H4O4 139.0036 139.0027 6.47 [M-H]- LC-MS

6 1,2,4,5-Benzenetetrol C6H6O4 141.0182 141.0183 -0.71 [M-H]- LC-MS

7 4-Chlorocatechol C6H5O2Cl 142.9905 142.9898 4.90 [M-H]- HPLC, LC-MS

8 Chloromaleic acid C4H3O4Cl 148.9647 148.9634 8.73 [M-H]- LC-MS

9 4-Chloro-5-hydroxy-1,2,-benzoquinone C6H3O3Cl 156.9697 156.9693 2.55 [M-H]- LC-MS

10 5-Chloro-1,2,4,-benzenetriol C6H5O3Cl 158.9854 158.9846 5.03 [M-H]- LC-MS

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Product No.

Compounds Chemical formula

Theoretical m/z

Observed m/z

Δ (ppm) Ionization

form Analysis method

11 (2E,4E)-3-Chloro-2.4-hexadienedioic

acid C6H5O4Cl 174.9792 174.9799 -4.00 [M-H]

- LC-MS

12 2-Chloro-5-hydroxy-2,4-hexadienedioic

acid C6H5O5Cl 190.9741 190.9976 -123.05 [M-H]

- LC-MS

13 5-Chloro-2,4-dihydroxybiphenyl C12H9O2Cl 219.0207 219.0214 -3.20 [M-H]- LC-MS

14 Dichlorobiphenyl C12H8Cl2 220.9930 221.0009 -35.75 [M-H]- LC-MS

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(a) Fluorescent lamp

Wavelength (nm)

200 300 400 500 600 700 800 900

Rel

ati

ve

inte

ns

ity

(b) Xenon arc lamp

Wavelength (nm)

200 300 400 500 600 700 800 900R

ela

tiv

e in

ten

sit

y

Fig. S1. (a) Light emission spectra of the fluorescent lamp and (b) the xenon arc lamp with a

400 nm longpass filter.

6

Fig. S2. Photographs of peroxo-TiO2 synthesized with varying H2O2 concentrations and

drying temperature, and photochemical degradation of 4-CP using synthesized materials

under visible light illumination (time-concentration profiles and pseudo first-order rate

constants): effects of H2O2 concentration ((a) – (c)) and drying temperature ((d) – (f))

([peroxo-TiO2] = 0.5 g/L, [4-CP]0 = 10 μM, pH = 5, I = 6.43 × 106 Einstein/L∙s (fluorescent

lamp, λ > 400 nm)

(e)

Illumination time (min)

0 60 120 180 240

[4-C

P]/

[4-C

P] 0

0.0

0.2

0.4

0.6

0.8

1.0 20oC50oC100oC200oC400oC

(f)

Synthesized temperature (oC)

20 50 100 200 400

Pseu

do

-fir

st

ord

er r

ate c

on

sta

nt,

k (

min

-1)

0.000

0.004

0.008

0.012

0.016

0.020

(b)

Illumination time (min)

0 60 120 180 240

[4-C

P]/

[4-C

P] 0

0.0

0.2

0.4

0.6

0.8

1.0 0.1 M0.5 M1.0 M2.0 M5.0 M10.0 M

(c)

H2O2 concentration (M)

0 0.1 0.5 1 2 5 10P

seu

do

-fir

st

ord

er

rate

co

nsta

nt,

k (

min

-1)

0.000

0.004

0.008

0.012

0.016

0.020

7

Fig. S3. (a) X-ray diffraction patterns and (b) HR-TEM images of peroxo-TiO2 prepared at different drying temperatures.

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(b)

Wave number (cm-1)

600800100012001400

Ab

so

rba

nc

e

0.0

0.2

0.4

0.6

0.8

1.0 Broad peak (940 - 820 cm-1)(Ti-2-peroxide functional group)

Wave number (cm-1)

860880900920940

Ab

so

rba

nc

e

0.0

0.1

0.2

0.3

(a)

Binding energy (eV)

526 528 530 532 534 536 538 540

Inte

ns

ity

(a

.u.)

Ti-O(529.8 eV)

Ti-OH(531.8 eV)

Fig. S4. (a) X‒ray photoelectron spectra (O 1s level) and (b) FT-IR spectra of TiO2 (Degussa P25).

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Illumination time (min)

0 60 120 180 240

[4-C

P]/

[4-C

P] 0

0.0

0.2

0.4

0.6

0.8

1.0Fluorescent lampXenon arc lamp

Fig. S5. Degradation of 4-CP by Am-peroxo-TiO2 under visible light illumination:

comparison of different light sources ([Am-peroxo-TiO2] = 0.5 g/L, [4-CP]0 = 10 μM, pH =

5, I = 6.43 × 106 Einstein/L∙s (fluorescent lamp, λ > 400 nm), I = 2.46 × 105 Einstein/L∙s

(xenon arc lamp, λ > 400 nm)).

10

11

(a)

Illumination time (min)

0 60 120 180 240

[XT

T f

orm

az

an

] (m

M)

0.0

0.2

0.4

0.6

0.8

1.0(b)

Wavelength (nm)

200 400 600 800 1000

Ab

so

rba

nc

e (

Ab

s.)

0

1

2

3

4

5

0 h4 h

Fig. S6. Formation of XTT-formazan ((a) time-concentration profile and (b) UV-vis absorption spectra) by Am-peroxo-TiO2 under visible

light illumination ([Am-peroxo-TiO2] = 0.5 g/L, [XTT]0 = 0.1 mM, pH = 5, I = 6.43 × 106 Einstein/L∙s (fluorescent lamp, λ > 400 nm)).

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Fig. S7. Repeated degradation of 4-CP by Am-peroxo-TiO2 under visible light illumination ([Am-peroxo-TiO2] = 0.5 g/L, [4-CP]0 = 10 μM,

pH = 5, I = 6.43 × 106 Einstein/L∙s (fluorescent lamp, λ > 400 nm)).

Illumination time (h)

0 2 4 6 8 10 12 14 16

[4-C

P]/

[4-C

P] 0

0.0

0.2

0.4

0.6

0.8

1.0

Illumination time (h)

0 2 4 6 8 10 12 14 16

13

Illumination time (min)

0 60 120 180 240

[Pro

du

cts]

( M

)

0

2

4

6

8BenzoquinoneHydroquinone4-Chlorocatechol

Fig. S8. Formation of oxidation products during 4-CP degradation by Am-peroxo-TiO2 under

visible light illumination ([Am-peroxo-TiO2] = 0.5 g/L, [4-CP]0 = 0.1 mM, pH = 5, I = 6.43 ×

106 Einstein/L∙s (fluorescent lamp, λ > 400 nm)).

14

(a)

Irradiation time (min)

0 60 120 180 240

Pe

ak

are

a (

Co

un

ts x

10

5)

0

1000

2000

3000

4000

5000 Product 7Product 9Product 10

(b)

Irradiation time (min)

0 60 120 180 240

Pe

ak

are

a (

Co

un

ts x

10

5)

0

50

100

150

200

250

Product 3Product 4Product 5Product 11Product 13Product 14

(c)

Irradiation time (min)

0 60 120 180 240

Pe

ak

are

a (

Co

un

ts x

10

5)

0

10

20

30

40

50

Product 1Product 6Product 8Product 12

Fig. S9. Formation of oxidation products during 4-CP degradation by Am-peroxo-TiO2 under visible light illumination ([Am-peroxo-TiO2] =

0.5 g/L, [4-CP]0 = 0.1 mM, pH = 5, I = 6.43 × 106 Einstein/L∙s (fluorescent lamp, λ > 400 nm)).

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Fig. S10. Formation of oxidation products during 4-CP degradation by Am-peroxo-TiO2 under visible light illumination: chromatograms of

oxidation products at 4 h with mass spectra ([Am-peroxo-TiO2] = 0.5 g/L, [4-CP]0 = 0.1 mM, pH = 5, I = 6.43 × 106 Einstein/L∙s

(fluorescent lamp, λ > 400 nm)).

16

(a)

Binding energy (eV)

526 528 530 532 534 536 538 540

Inte

ns

ity

(a

.u.)

Ti-OH(531.8 eV)

Ti-O(529.8 eV)

Ti-OOH(533 eV)

(c)

Binding energy (eV)

526 528 530 532 534 536 538 540

Inte

ns

ity

(a

.u.)

Ti-OH(531.8 eV)

Ti-O(529.8 eV)

Ti-OOH(533 eV)

(b)

Binding energy (eV)

526 528 530 532 534 536 538 540

Inte

ns

ity

(a

.u.) Ti-OH

(531.8 eV)

Ti-O(529.8 eV)

(d)

Binding energy (eV)

526 528 530 532 534 536 538 540

Inte

ns

ity

(a

.u.)

Ti-OH(531.8 eV)

Ti-O(529.8 eV)

Ti-OOH(533 eV)

Fig. S11. X-ray photoelectron spectra (O 1s level) of (a, b) Am-peroxo-TiO2 and (c, d) Pt-

Am-peroxo-TiO2 (a, c) before and (b, d) after 4-CP degradation under visible light

illumination ([Am-peroxo-TiO2]0 = [Pt-Am-peroxo-TiO2]0 = 0.5 g/L, [4-CP]0 = 10 μM, pH =

5, I = 6.43 × 106 Einstein/L∙s (fluorescent lamp, λ > 400 nm)).

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Fig. S12. Diffuse reflectance spectra of (a) Am-peroxo-TiO2 and (b) Pt-Am-peroxo-TiO2

before and after 4-CP degradation under visible light illumination ([Am-peroxo-TiO2]0 = [Pt-

Am-peroxo-TiO2]0 = 0.5 g/L, [4-CP]0 = 10 μM, pH = 5, I = 6.43 × 106 Einstein/L∙s

(fluorescent lamp, λ > 400 nm)).